Okay, is it an Inland barrel? What's the barrel date? If the barrel goes with the receiver, the bayo lug would have been installed by the military during an upgrade/overhaul. If the finish is original (blued) it might be worth putting on the correct band. If it has been parkerized, you may as well leave it as is.
I-44, are you saying a 600K Inland would have originally had a blued barrel rather than parkerized? - Bob